class Solution {
public:
    bool checkIfPangram(string sentence) {
        int i=0;
        int a[26];
        memset(a,0,sizeof(a));
        while(i<sentence.length()){
            a[sentence[i]-97]++;
            i++;
        }
        for(int i=0;i<26;i++){
            if(a[i]==0)return false;
        }
        return true;
    }
};
